METHOD AND APPARATUS FOR IMPROVING THE VOICE QUALITY OF TANDEMED VOCODERS

摘要

In recent years, the telecommunications industry has witnessed theproliferation of a variety of digital vocoders in order to meet bandwidthdemands of different wireline and wireless communication systems. The rapidgrowth in the diversity of networks and the number of users of such networksis increasing the number of instances where two vocoders are placed in tandemto serve a single connection. Such arrangements of low bit-rate codecs candegrade the quality of the transmitted speech. To overcome this problem theinvention provides a novel method and an apparatus for transmitting digitizedvoice signals in the wireless communications environment. The apparatus iscapable of converting a compressed speech signal from one format to anotherformat via an intermediate common format, thus avoiding the necessity tosuccessively de-compress voice data to a PCM type digitization and thenrecompress the voice data.